Field of the Invention
This invention concerns heating water or other fluids using pulse combustion. See U.S. Pat. No. 5,793,119 issued on Aug. 11, 1998 which describes heating thermoelectric components using pulse combustion.
A major problem with steam boilers and hot water heaters is the poor efficiency of the process. This poor efficiency of converting fossil fuel energy into heat for water can be improved somewhat if externally augmented by auxiliary power such as electrically powered flue blowers. This is often done but the improvement in combustion efficiency is offset by the consumption of costly electrical power.
Water can be heated more efficiently with pulse combustion because part of the fossil fuel combustion energy is used to force the flue products through the chimney. Because this forcing action is present with pulse combustion, flue products may be cooled below the temperature needed to provide sufficient chimney draft and this allows designs which transfer more heat from the combustion exhaust products to the water. Present pulse combustion water heater designs, however, are limited in that they cannot heat the water to a higher temperature than the flue products and still be efficient at colder water temperatures. This is because the combustion process is not sustainable at higher water temperatures with present designs.
Currently existing pulse combustion hot air furnaces are capable of operating indefinitely because the heated air delivered to the building's warm air registers is always colder than the combustion products in the furnace exhaust flue.